The number of confirmed cyclosporiasis cases, the parasitic intestinal illness that often results in watery diarrhea and explosive bowel movements, has more than doubled in the past week, the Maryland Department of Health confirmed Wednesday.

The total number of cases in the state is now 69, with 65 of those cases occurring since May 1, according to the health department. The total number of domestically acquired cases nationwide has reached 1,645 across 34 states — more than six times as many as this time last year, according to the Centers for Disease Control and Prevention.

A report Tuesday from the CDC said 9% of the confirmed cases nationwide resulted in hospitalization, and no deaths have been recorded.

While Maryland hasn’t identified a common link in its cases, previous cyclosporiasis outbreaks have been connected to the consumption of fresh produce, and other states, such as Michigan, have pointed to lettuce or salad greens as a potential culprit.

Some produce vendors and farmers in the state say they haven’t noticed any effect on sales, but there have been concerns from customers.

Kelly Harding, who works at Don’s Farmers Market in Pikesville, said customers bring it up “more and more each day.”

“We hear a lot of people say they don’t want to get their stuff from the grocery stores,” Harding told The Baltimore Sun.

Vendors at produce markets in Baltimore’s Lexington Market and Northeast Market told The Sun there haven’t been any problems with sales and few, if any, people have mentioned it.

The Piney Orchard Farmers Market in Anne Arundel County hasn’t seen signs that shoppers are shying away from fresh produce, spokesperson Emily Sabelhaus said. She told The Sun that farmers have not expressed concerns about the outbreak, and customer turnout has remained fairly steady.

“People are really into the farmers markets,” Sabelhaus said. “They’re really into getting fresh produce” instead of produce that has spent time in warehouses and distribution centers.

Sabelhaus said market organizers communicate with farmers weekly and encourage customers to wash and properly store fresh produce at home — advice she maintains aligns with public health officials’ recommendations.

The intestinal illness, which is caused by a microscopic parasite called cyclospora, is transmitted through contaminated food, as opposed to person-to-person, and symptoms tend to appear one to 14 days after contamination. If untreated, symptoms could last for a few days up to a month or longer, according to the health department.

The sharp increase in cases this summer has prompted health officials to investigate whether the illnesses can be traced to a common source, though it’s still unclear whether one contaminated food item or multiple sources are responsible, said Karen Kotloff, chief of the Division of Infectious Diseases at the University of Maryland School of Medicine.

Tracing such outbreaks can be especially challenging because symptoms often don’t appear until up to two weeks after someone eats contaminated food, making it difficult for patients to remember what they consumed.

The parasite also isn’t included in many routine tests for diarrheal illnesses, meaning physicians often have to specifically suspect cyclospora and order additional testing, Kotloff said. Fresh produce commonly linked to the parasite — including leafy greens, herbs and berries — is also widely consumed, further complicating efforts to identify a single source.

Since Maryland’s large cyclospora outbreak in 1997, public health officials have gained access to faster and more sophisticated diagnostic tests, helping identify infections more quickly than in past decades, Kotloff said. Even so, investigators still rely on interviews with patients and painstaking traceback efforts to determine where contaminated food originated.

The CDC reported there are 5,100 cases that require further analysis to confirm whether or not it is cyclosporiasis. Although the outbreak has grown substantially this year, Kotloff said the infection is treatable with antibiotics, and many people recover on their own.

The number of confirmed cases is “certainly higher,” as many people will have a minor illness and recover without getting tested, according to the CDC.

According to the Maryland Department of Health, there were 204 confirmed cases in 2024, including 19 reported between May 1 and July 7, 2024. In 2025, there were 128 confirmed cases, with 18 reported between May 1 and July 7.

Outside of watery diarrhea and explosive bowel movements, symptoms include extreme fatigue, loss of appetite, substantial weight loss, increased gas, stomach cramps, nausea and low-grade fever.

The health department recommends washing fruits and vegetables before eating, avoiding water from untreated sources, avoiding touching human and animal feces and cooking food to 185 degrees Fahrenheit.

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